Effect of Inter-Reader Variability on Diffusion-Weighted MRI Apparent Diffusion Coefficient Measurements and Prediction of Pathologic Complete Response for Breast Cancer
Nu N. Le,
Wen Li,
Natsuko Onishi,
David C. Newitt,
Jessica E. Gibbs,
Lisa J. Wilmes,
John Kornak,
Savannah C. Partridge,
Barbara LeStage,
Elissa R. Price,
Bonnie N. Joe,
Laura J. Esserman,
Nola M. Hylton
Affiliations
Nu N. Le
Department of Radiology & Biomedical Imaging, University of California, San Francisco, CA 94158, USA
Wen Li
Department of Radiology & Biomedical Imaging, University of California, San Francisco, CA 94158, USA
Natsuko Onishi
Department of Radiology & Biomedical Imaging, University of California, San Francisco, CA 94158, USA
David C. Newitt
Department of Radiology & Biomedical Imaging, University of California, San Francisco, CA 94158, USA
Jessica E. Gibbs
Department of Radiology & Biomedical Imaging, University of California, San Francisco, CA 94158, USA
Lisa J. Wilmes
Department of Radiology & Biomedical Imaging, University of California, San Francisco, CA 94158, USA
John Kornak
Department of Epidemiology and Biostatistics, University of California, San Francisco, CA 94158, USA
Savannah C. Partridge
Department of Radiology, University of Washington, Seattle, WA 98195, USA
Barbara LeStage
I-SPY 2 Advocacy Group, San Francisco, CA 94143, USA
Elissa R. Price
Department of Radiology & Biomedical Imaging, University of California, San Francisco, CA 94158, USA
Bonnie N. Joe
Department of Radiology & Biomedical Imaging, University of California, San Francisco, CA 94158, USA
Laura J. Esserman
Department of Surgery and Radiology, University of California, San Francisco, CA 94143, USA
Nola M. Hylton
Department of Radiology & Biomedical Imaging, University of California, San Francisco, CA 94158, USA
This study evaluated the inter-reader agreement of tumor apparent diffusion coefficient (ADC) measurements performed on breast diffusion-weighted imaging (DWI) for assessing treatment response in a multi-center clinical trial of neoadjuvant chemotherapy (NAC) for breast cancer. DWIs from 103 breast cancer patients (mean age: 46 ± 11 years) acquired at baseline and after 3 weeks of treatment were evaluated independently by two readers. Three types of tumor regions of interests (ROIs) were delineated: multiple-slice restricted, single-slice restricted and single-slice tumor ROIs. Compared to tumor ROIs, restricted ROIs were limited to low ADC areas of enhancing tumor only. We found excellent agreement (intraclass correlation coefficient [ICC] ranged from 0.94 to 0.98) for mean ADC. Higher ICCs were observed in multiple-slice restricted ROIs (range: 0.97 to 0.98) than in other two ROI types (both in the range of 0.94 to 0.98). Among the three ROI types, the highest area under the receiver operating characteristic curves (AUCs) were observed for mean ADC of multiple-slice restricted ROIs (0.65, 95% confidence interval [CI]: 0.52–0.79 and 0.67, 95% CI: 0.53–0.81 for Reader 1 and Reader 2, respectively). In conclusion, mean ADC values of multiple-slice restricted ROI showed excellent agreement and similar predictive performance for pathologic complete response between the two readers.
